You can find info about the transaction by doing yum history info <transaction id>. So:

yum history info 19 would tell you all the packages that were installed with transaction 19 and the command line that was used to install the packages. If you want to undo transaction 19, you would run yum history undo 19.

Alternatively, if you just wanted to undo the last transaction you did (you installed a software package and didn't like it), you could just do yum history undo last

Firstly, thank you for your excellent answer. And secondly, when I did sudo yum history, it showed only actions with id 30 through 49. Is there a way to view all actions history (including with id 1-29)?
– ukllAug 16 '16 at 18:34

1

You're welcome! Yes, there is a way to show all of your history. Just do yum history list all.
– Jason PowellAug 16 '16 at 19:00